Transmission



Nov. 30, 1937.

W. T LIVERMORE TRANSMISSION 4 Shets-Shee't 1 Filed Jan. 5, 19s2WILLIArIZ'ERIE-RM RE ATIIO NEY Nov. 30, 1937. w. T. LIVERMORETRANSMISSION Filed Jan. 5, 1932 4 Sheets-Sheet 2 mQN INVENTOR WILLIAM ELIVERMORE A OREY NOV. 30, 1937. w T. LIVERMORE 2,100,810

TRANSMISSION Filed Jan. 5, 1952 4 Sheets-Sheet 3 A {Page 3G2 'INVENTORWILLIAM T LIVERMORE BY W ATTORNEY Nov. 30, 1937. w. T. LIVERMORE2,100,810

TRANSMISSION Filed Jan. 5, 1932 4 Sheets-Sheet 4 FIG. 9.

INVENTOR WILLIAM T L'IVERMORE TTORNEY Patented Nov. so, 1931 UNITEDSTATES PATENT OFFICE 14 Claims.

This invention relates to transmissions and in particular to a typeadapted for use in-connection with an automotive vehicle.

Among the most important objects of my invention are means for operatinga transmission which will eliminate any interruption of power flow froman engine to the wheels of the vehicle during speed changes thus givingfaster and 20 as a conventional gear transmission and embodies theadvantages of the gas electric, synchro-mesh, and free wheeling withnone of their disadvantages and at a lower cost than synchro-mesh plusfree wheeling.

25 Changes and variations may be made in the construction shown anddescribed without de-' parting from the principles of the invention orsacrificing its chief advantages; hence such invention is not to beconfined to the structures 30 shown in the accompanying drawings; inwhich; Figure 1 is a view in section of a transmission constructed inaccordance with my invention.

Figure 2 is a view in cross section taken substantially on the line 2-2of Figure 1, the same 35 illustrating the pressure means for engagingthe clutches, the pump and the speed shift arrangement.

Figure 3 is a section taken on the line 3-3 of Figure 2 and illustratesthe free wheeling feature 40 and the valve control cam for permittingselective operation of the clutches.

Figure 4 is a section taken on the line 4,-4 of Figure 2, theillustration being similar to the illustration of the valve control camillustrated in.

45 Figure 3.

Figure 5 is a plan view of the lever guide plate employed in connectionwith the gear shift lever.

Figure 6 illustrates diagrammatically the conventional lever shift inconnection with my trans- 50 mission.

Figure 7 is a section taken on the line 1-1 of Figure 2.

Figure 8 is a view in sectional elevation of a modified form of myinvention. 55 Figure 9 is a diagrammaticview of the hydraulic operatingmechanism used in connection with the transmission illustrated in Figure8.

Figure 10 is a plan view of the mechanism connected with the shift leverillustrated in Figure 9.

Referring to the drawings in detail, 50 indicates 5 the transmissionhousing at one end of which operates the fly wheel 5i connected to themotor shaft in the usual manner. The fly wheel receives the reduced end52 of a drive shaft I03, further reference to which will be madehereinafter. The 10 opposite sides of the flywheel structure arearranged to support between them,-the disk pins 53 carrying slidably,the friction clutch rings 54 and 55 which are disposed between theclutch disks, the ring 54 being disposed between the clutch disks i0!and NH and the ring 55 being disposed between the clutch disks I02 andloll-C, the parts lllI-C and I02--C being movable as will be hereinafterdescribed to have operative engagement with the friction clutch rings 9054 and 55 respectively.

The clutch disk elements It'll and illl-C are separated by a spring l0l-A and are each splined to the shaft I03 which constitutes the maindrive shaft and is provided with the splined portions Hill-A and I03-15, to the portion lli3-A of which is splined, the high speed driveclutch llil and lDl-C.

A sleeve shaft H0 is revolvably mounted over the tube H2 which has asliding fit on the drive shaft I03, said tube abutting the member "ll-Cof the high speed clutch at one end and at the opposite end carrying thethrust ball bearing 24 l-A which is arranged to be engaged by a suitableoperating yoke to cause longitudinal movement of the tube 2 tooperatively connect the parts llIl --l0|C of the high speed clutch todirectly drive the shaft I03. The sleeve H0 is provided at one of itsends with the gear teeth Ill and splined at its opposite end as atElli-C to receive. the parts I02, 12-0 of the first and second speed andreverse drive clutch, which are normally maintained in separatedrelation by the spring l02--A. The part ll|2-C of the clutch combinationis itself extended to provided a clutch sleeve H3 upon which is mountedthe thrust ball bearing II-A which is also arranged to be engaged by asuitable yoke so that the part l02--C of the clutch combination can bemoved into engagement with the ring 55 and thru part I02 to provide adrive for the sleeve 0.

In the transmission casing there is also provided a countershaft 56 andrevolvably mounted thereon is the countershaft sleeve I04 provided wi hthe gear parts or sections I05 and I05 and I01. The countershaft I08suitably journalled in the casing 50 carries the reversing idler gearI03 which is shaped to receive in the well known manner, an operatingyoke to be hereinafter referred to. The gear section I05 of thecountershaft sleeve I04 is arranged to mesh with the gear teeth III ofthe sleeve 0 while the gear section I06 provides for the first speed ofthe vehicle when the gear II4 splined as at I03-B to the shaft I03 is inmesh therewith. This gear II4, provided with the usual gear teeth, isalso provided with the dog clutch teeth I I6 which are arranged toengage similar dog clutch teeth in the second speed gear H5 mounted forfree rotation with respect to the shaft I03. The gear H4 is providedwith yoke engaging means wherebyit also may be moved for change inspeed. The shaft I03 at its opposite end carries a suitable connectingplate 60 through the medium of which the drive may be transferredtoanother operating part.

In the operation of the device thus far described, direct high speeddrive is obtained by moving the parts IOIC of the clutch combinationagainst the clutch ring 54 and against the part I0l so that the drivefrom the fly wheel 5! is transferred through the clutch parts IOI, IOI-Cdirectly to the shaft I03. First speed drive is obtained by operatingthe ball thrust bearing.

240--A to move the sleeve II3 so that the parts I02, I02-C of the clutchcombination are in operating engagement with ring 55 and are driven bythe fiy wheel 5I, thus transferring the drive from the fly wheel to thedrive sleeve I I0, which in turn, transfers the drive by the teeth I I Imeshing with the gear I05 to the countershaft sleeve I04. Operation ofthe gear II\4 along the drive shaft I03 until it meshes with the gearI06 will cause drive through the shaft I03 to provide first speed.Second speed is obtained by having the dog clutch teeth I I6 of the gearI I4 in mesh with the clutch teeth of the gear II5 which in turn isdriven from the gear portion I01 of the countershaft I04, thus drivingthrough the gear I I4 back to the drive shaft I03.

Reverse drive of the vehicle is obtained by moving the reverse idler I09and also the gear .I I4 until 'a drive is effected between the gear I06of the countershaft I04 through gear I09, through gear II4 to the shaftI03; thus the clutch parts I02, I02-C provide first and second speed aswell as reverse speed, while the parts IM and IOI-C of the clutchcombination provide for direct or highspeed drive.

The operation of the gear I I4 is provided by the yoke II4A carried bythe longitudinally movable shifter rod 23I which is journalled in thetransmission housing and has its end disposed in position to be engagedby-the depending shift lever pin 22'IA which, in turn, is secured to theend of the shaft 228 suitably journalled in the housing and arranged tocarry at its outer end a clutch valve cam 2I6, this shaft 228 beingrevolvable as well as movable longitudinally so that the shifter pin canbe placed in the notch 6| of the bar 23I or in a similar notch in thereverse bar 232. Referring to Figure 1, it will be noted that theshifter bar 23I beyond the notch 6| in which is positioned the ball endof the shifter pin is provided with an arcuate incline 62 so that, asshown in Figure 1, when the shifter pin 22'IA moves to the left, asufficient distance, to move the bar 23I until the ball end of theshifter pin 22'I-A is beyond the upper edge of the notch or slot 6|,said ball end will ride up on the surface 62 and permit an additionalrocking movement of the cam 2I6 without affecting theposition of theshift bar 23I. The bar 232 is also provided with a similar surface 63but disposed oppositely to the surface 62 of the bar 23I so that whenthe shifter pin is moved to the right and moves, the bar 232 with ituntil it clears the notch therein, it will ride up along the surface 63and permit an additional revolving movement of the clutch valve cam 2I6without moving the bar 232 lon tudinally. The position of each tratedthe clutch valve cam, which, as before noted, is operated by a revolvingmovement of the shaft 228 and has pressed against its under surfacethrough the medium of the push rods 2I2, 2I3, the rock levers 2I4 and2I5 respectively which are journalled on the stud 66 at opposite sidesof the free wheeling lever 229 and rod 230, the latter of which isconnected with the accelerator pedal 65 in any suitable manner. A spring65a is provided for normally holding the accelerator pedal in closedposition, said spring being shown surrounding the throttle control rod65b.

The operation of the control valve is governed by the position of theclutch valve cam 2I6 and the accelerator pedal 65. When the acceleratorpedal is in the normal position, that is, closed throttle, the two lugs223, 224 on the free wheeling lever 229, through engagement with thecorresponding lugs 225, 226 on the rock levers 2I4 and 2I5, preventeither of the rock levers from raising and thereby opening control valveregardless of the position of the clutch v-alve cam 2I6. Therefore, bothclutches I M and I02 are always disengaged when the throttle pedal is innormal position. This disengagement of the clutches provides a freewheeling feature by preventing driving connection between the source ofpower and the driving shafts. Hence the lever 228 is referred to as afree wheeling lever. The clutch valve cam 2I6 is movable in twodirections and this motion is controlled entirely by the shifter leverpin 22IA and shifter lever shaft 228. Manual movement of the shifterlever 221, see Figure 2, to the right or left slides the shifter levershaft 228 to the left or right which brings the depressed faces of theclutch valve cam 2I6 into or out of longitudinal alignment with the rocklevers 2I4 and 2I5. Fore and aft manual movement of the shift leverrotates the clutch valve cam 2I6 with shifter lever shaft 228 whichbrings the cam faces on 2I6 into or out of contact with the rock levers2I4 or 2I5 depending upon the particular lateral position of the cam. Inthis manner manual control of the control valve is obtained. Theparticular speed controlled by each face on clutch valve cam isdesignated on the drawings, Figure 2, in which the points indicated bythe numeral I0, II, I2 and I3, are the faces or the depressed portionswhich operate the levers 2I4 or 2I5 to give high speed, first speed,reverse speed and second speed, respectively. For the purposes of speedcontrol over the countershaft sleeve I04 while changing speeds orto makeit possible to spin the countershaft sleeve I04 for easy engagement ofthe gears when the car is not moving, a depressed face 2I6-E is formedon the clutch valve cam 2 l which engages clutch I02 through the mediumof the mechanism to be described and which is controlled by the rockerlever 2|5 when moving from first to second speed thus giving effect to adouble clutching action. Lateral and longitudinal movement of theshifter lever 221 selects the gear and further longitudinal'movement ofthe lever 22] opens or closes the control valve. In lateral movementlever 22'! engages the shifter rods 23| and supported on the spring 15and also resisting the action of the spring 16 which holds in place aball check valve 203 so that intake of oil is permitted from the sump204 formed in the casing, through the passage 203--A' into the plungerchamber 203-C from whence it is forced out through the passage 203-Einto the pressure chamber 206 in which air has been pocketed to form anair cushion 206-A. A suitable check valve 205 is positioned between thepassage 203--E and the pressure chamber 206, the pressure on the checkvalve, which is of ball formation, being kept through the medium of thespring 205-A and threaded plug 205-eE. The oil pressure chamber 206opens into a passage 201 which connects with the control valve plungerchambers 2|0-E and 2| |E, (see Figure 1), in which are disposed theplungers 2|0A and 2| |A, respectively. Each of the plungers 2|0A and 2||A are provided with the diametrically disposed vertical slots 222 and222-A respectively and are each mounted on the springs 11 operatingagainst the ball valves 2| |B and 2|0B which are positioned in thechambers 2 0E and 2| |E respectively to admit oil under pressure fromthe passage 20! when the pressure is removed or decreased from either ofthe springs 11 by the raising of the plungers-2 |0A or 2| |--A whichmovement is permitted by operation of either of the levers 2|4 or 2|5being forced into the various cam seats of the clutch valve cam 2|8. Theupward movement of the plungers 2|0A or 2||-A is transmitted to thelevers 2 or 2|5 through the medium of the lifter rods 2|2E or 2|3-Eengaging the lever push rods 2|2 and 2|3, the push rod 2| 2 engaging thelever 2|4 while the push rod 2|3 engages the lever 2|5. The chambers2|0--E and 2| |E are closed through the medium of suitable bushings andconnect with adjacent clutch operating plunger cylinders 2|9-A and 220-Athrough the medium of the bores 18 into which extend the threaded studs19 constituting chokes or choke plugs which are adjustably threaded inthe bottom cover plate 204C which closes the sump space 204 and whichcarries the control valves and operating plungers all in one castingwhich bolts to the transmission housing. With this construction anyleakage from the plungers or control valves flows directly into the sumpspace. This also eliminates the necessity for piston rings on theplungers and makes the entire mechanism very compact and accessible. Theend of the oil pressure passage beyond the ball check valves 2|0B and2||B is closed by the relief ball valve 208 which is seated by pressurefrom the spring200-A but yields at a predetermined pressure to permitthe oil to flow past the ball valve 208 through the relief valve passage203 and back into the sump space 204. The pump plunger 202 is operatedby the fly wheel cam 20|.

In each of the clutch operating plunger cylinders 2|3-A and 220-A thereis positioned respectively, a first and second speed clutch operatingplunger 2|! and a high speed clutch operating plunger 220 each beingprovided with an air cushion pocket 80 in its lower end. Oil admittedunder pressure through either of the ball valves 2|0B or 2| |--B toeither of the chambers 2|9-A'or 220-A will operate either of theplungers 2|0 or 220 depending upon the position of the cam 2|0. Theseplungers operate respectively the push rods 2|0E, 220E, the rod 2|3Eoperating the clutch, operating lever 2|I while the rod 220-E operatesthe clutch operating lever 2|8. Both these clutch levers are pivoted onthe stud 233. The lever 2|8 through a push rod 231 operates a bell crank238 pivoting with stud 239 which in turn operates a fork or yoke 24| tomove the high speed clutch bearing 24| A to permit high speed drivethrough shaft |03.

The lever 2 l1 turns the bell crank' 234 through engagement with lug235. The bell crank 234 turns pin 238 and operates the fork or yoke 240which bears against the thrust bearing 240-A to afford drivingconnection between the parts of the first, second and reverse speedclutch. The rate of application of the clutches is controlled by thehand lever 22! through the partial or full I opening of the controlvalves and through this medium the clutch may be slipped, or partiallyapplied.

Suitable drain openings 2|0H are provided in each of the chambers 2| 0E,2| |E to permit expulsion of the liquid from said chambers into the sumpchamber 204, when the cam 2|8 is operated to depress the plungers 2|0Aor 2| l-A.

A modified form of my invention is illustrated in Figures 8 and 9, thetransmission incorporated in the modification being particularly adaptedto the use of five speeds as employed in the design of buses and trucks.In this form of my invention there are five forward speeds and tworeverse speeds. There is only one mechanical shift between second andthird speed which involves engaging gear 304 with gear 3|2 through thejaw clutch 3|2--A. In all speeds, the various ratios are obtainedthrough engagement of one of the three clutches. The engagement anddisengagement of the clutches is controlled by the hydraulic mechanismshown diagrammatically in Figure 9.

Referring to the hydraulic mechanism, a gear pump 320 driven in anysuitable manner from the engine, draws oil from a supply chamber 32| andpumps it into a pressure chamber 322 in the upper portion of which isprovided an air 4 the selector valve 334 to the expandible-bellows 328,one being employed as at 328 to operate the push rod for manipulation ofthe third and first speed clutches. The bellows 329 operate the secondand fourth speed clutches and the bellows 330 operate the fifth speedclutch providing direct drive. The clutch valve 321 is cylindrical andacts as a plunger within the valve cylinder 326 and is provided with theside groove 33l which affords passage of the liquid under pressure tothe selector valve 334. The selector valve comprises the casing 332which is connected through the medium of the pipe 333 to the oil supplytank and by the pipe 334A is connected to the clutch valve chamber 326.In this selector valve housing, there operates a selector valve plunger334. Each of the bellows 328, 329 and 330 are connected through themedium of their respective pipes 335, 336, and 331 to the selector valvechamber 332. The selector valve 334 is provided with suitable grooves sothat oil may flow from the pipe 334-A to any one of the bellows pipes335, 336.

or 331 depending upon the position of the selector valve plunger 334.The position of the valve 334 is regulated by the gear change orselector lever 338. The selector valve 334 is also provided withopenings 339 which permit fiow of the oil or drain thereof from thebellows not under pressure back to the oil supply tank.

The foot valve performs the same function as the ordinary clutch pedal.By pushing the pedal down, which is indicated by the numeral 340, theclutch which is engaged is released and by letting it up, the clutch canbe gradually en gaged. This valve holds a ball valve 343 on its seat byspring pressure, thus resisting the flow of oil to the selector valve.As the valve is raised,

the spring pressure is released from the ball and allows the oilpressure in the bellows to increase. If the valve is pushed down untilthe upper groove 34l therein connects the passage 334-A with the passage342 which leads back to the oil supply tank, the oil flows out of thebellows and releases the clutch. In driving the truck, the foot valve isused only for maneuvering when the truck is to be moved a short distanceat a time or in making a very gradual start. It is not touched duringnormal driving. For starting, the selector lever 338 can be moveddirectly into the first speed position without touching the pedal. Inorder that the clutches may be eased in, use is made in the pipes 335,336, and 331 connecting the selector valve with the respective bellows,of chokes 310, 31!, and 312 which are in the nature of set screws whichmay be threaded into the pipes to block the passage thereof so that thepressure is admitted easily to the bellows 328, 329, and 330.

In connection with all of the bellows, there is employed, an air cushion313 but only illustrated in connection with bellows 329, this aircushion being provided by the air caught in the bellows when the oil orother fiuid under pressure is forced into the bellows, this air cushionalso providing ease of operation of the clutches and gives the gradualthrow-in of the clutch that avoids jarring in starting the vehicle.

In Figure 8, illustration is made of the bellows 328 in its relation tothe transmission mechanism, it being understood that all of the bellows328, 329 and 330 are disposed so as to move through the push rods 330A,the yokes 350, 35!, and 352, respectively, the yokes 350 and 35! beingarranged to move longitudinally the shafts 353 and 354 respectively tocause operation of the clutches 3l0 and 3| l respectively. The clutch3l0 is employed for the purposeof providing first V speed and also thirdspeed while the clutch 3 is employed to obtain second and fourth speed.The clutch 3| 3 operated by the yoke 352 and by bellows 330 is employedto give fifth speed as direct drive.

It is to be noted that all of the sylphon bellows and the valves are tobe carried on a casting bolted to the side of the clutch housing 358,the clutch housing to act as a sump for the hydraulic fluid.

First speed, as all other speeds, except direct drive, is obtained fromthe fly wheel 360 operating through the toothed disk 3l3-A to drive thesleeve 36l mounted on the' drive shaft 362 and provided with-the gear30l whichin meshing with the gear 302 carried on the countershaft 363and fixed thereto, operates said shaft 363 and through the clutch 3l0when the same is actuated by the means previously described, drivesthrough the countershaft sleeve 364 to operate gear 304 splined on theshaft 362 and movable through the medium of a suitable yoke 362-E, tomesh with the gear 303 formed as an integral part of the countershaftsleeve 364. This countershaft sleeve also carries the gear 309 as anintegral part thereof but the operation of the gear 303 with the gear304 serves to drive the shaft 362 thus providing first speed. The gear3l2 mounted loosely on the shaft 362 engages the gears 301 and 309 toprovide in combination with the sleeve 364, and gear 304, the secondspeed drive. When the clutch 3 is operated by the bellows 329 itprovides drive through the clutch 3 by shaft 365, to which is keyed thegear 306 which meshes with gear 305 formed on the sleeve 36 l. Secondspeed is obtained by a drive through the members 3I3A, 36!, 305, 306,365, 301, 3l2, 309, 364, 303, 304, and 362.

Third and fourth speeds are provided in the same manner as the first andsecond speeds but with the jaw clutch 3l2-A and 3l2-B engaged, the thirdspeed being provided by the sliding gear 304 on the main shaft engagedwith gear 3l2 through the teeth of the jaw clutch or gear 3l2, the teethbeing indicated by the numeral 3 l2-A. The power then flows from the flywheel through the gears 30!, 302, 309, 3l2, 304 to the main shaft 362with the clutch 3l0 engaged.

For fourth speed, the power flows through the gears 305, 306, 301, 3l2,304 to the main shaft 362 with the clutch 3H engaged.

The gear change or selector lever 338 is mounted on the shaft 315 whichis journalled for rocking and longitudinal movement in suitable supports 316, the shaft 315 carrying the arm 311 which engages the upperend of the selector valve 334 so that a rocking movement of the shaft315 will raise and lower the selector valve 334. The shaft 315 alsocarries the spool 318 which operates the rocker lever 319 which in turn,engages a yoke 362-E mounted for sliding movement on a countershaft 380.

Fifth or direct drive is obtained by engagement of the clutch 3| 3 todrive directly through the shaft 362. Reverse drive is obtained byshifting reverse gear 304-E to mesh with 303 and 304 which aredisengaged from each other by slight movement of 304.

My invention is not to be restricted to the precise details ofconstruction shown since various changes and modifications may be madetherein without departing from the scope of the invention or sacrificingthe advantages derived from its use.

What I claim is:-

1. In a transmission, a driving member, drive shafts, clutches foroperatively connecting said member and shafts, means for actuating theclutches including members having expansible chambers, a source of fluidpressure, means for admitting the fluid under pressure to the expansiblechambers to actuate the clutches including a single control member, anda choke for controlling the rate of application of the fluid to theexpansible chambers.

. 2. In a transmission, a driving member, a drive shaft, a clutch foroperatively connecting said member and shaft, means for actuating theclutch including an expansible member having an air cushion boretherein, means for admitting fluid under pressure to the clutchactuating means, means forcontrolling the rate of clutch actuation, andother means for altering the rate of clutch actuation.

3. The combination with a selective gear transmission having a drivingshaft and a driven shaft, a plurality of change speed gears interposedbetween said driving and driven shafts and means for shifting at leastone of said gears to efiect different gear ratios between said drivingand driven shafts, a pair of clutches one for establishing directdriving relationship between said driving and driven shafts and theother for establishing driving relationship between said shafts throughsaid change speed gears, means for actuating said clutches and a singlemanually operable control member for controlling said clutch actuatingmeansand said gear shifting means.

4. In a transmission, a driving shaft and a driven shaft, a speed changegear mechanism interposed between said driving and driven shafts and apair of clutches one for establishing driving connection directlybetween said driving and driven shafts and the other for establishingsaid connection through said gear changing mecha- Y nism, fluid pressureactuated means for engaging said clutches, means for shifting the speedchange mechanism to establish different gear ratios between said drivingand driven shafts, a manually operable lever for selective engagementwith said gear shifting means, means for controlling the flow of fluidto said fluid actuated means and means connected with said lever forengagement with said fluid pressure control means to cause the gearshifting and clutch engaging operations to be efiected in sequence.

5. The combination with a sliding gear transmission for an automotivevehicle having a driving shaft and a driven shaft, a plurality of changespeed gears interposed between said driving and driven shafts and amanually operable gear shift lever for selectively establishingconnection 'of different gear ratios ofa pair of clutches one forestablishing direct driving connection between said driving and drivenshafts and the other for establishing driving connection through saidchange speed gears, fluid pressure actuated means said shafts inoperative driving relationship, fluid pressure actuated means forcausing engagement of said clutch means, a pump for supplying fluidunder pressure to said fluid pressure actuated means and means forpreventing jerky clutch engagement including cushioning means in saidfluid I pressure actuating means and a choke interposed between saidpump and said cushioning means.

7. In a fluid pressure actuated change speed transmission including adriving shaft and a driven shaft and clutch means for connecting saidshafts in operative driving relationship, fluid pressure actuated meansfor causing engagement of said clutch means, a pump for supplying fluidunder pressure to said fluid pressure-actuated means and means forpreventing jerky engagement of said clutch means comprising a reservoirconnected with said pump for maintaining a reserve supply of fluid underpressure, means communicating with said reservoir to compensate forrapid volumetric variations of the fluid contents under pressuretherein, connections between said pump and said fluid pressure actuatingmeans communicating with the latter below the top thereof to insure thetrapping of a volume of air in said fluid pressure actuated means toprovide an air cushion immediately adjacent to said clutch actuatingmeans and a choke interposed between said pump and fluid pressureactuated means to prevent too rapid building up of pressure therein.

8. In a fluid pressure actuated change speed transmission, a drivingshaft and a driven shaft, means for establishing a plurality ofdifferent driving ratios between said driving and driven shaftsincluding clutch means, fluid pressure actuated means for operating saidclutch means, a manually operable control member interposed between saidsource of fluid pressure and said fluid pressure actuated means forselectively rendering said different speed ratios eflfective and meansincluding said control member for varying the pressure of the fluiddelivered to said fluid pressure actuated means from said source. 9. Thecombination with an automobile having a throttle controlled engine, of afluid pressure actuated change speed transmission, a driving shaft and adriven shaft, means for establishing a plurality of different drivingratios between said driving and driven shafts including clutch means,fluid pressure actuated means for operating said clutch means, amanually operable control memb er interposed between said source offluid pressure and said fluid pressure actuated means for selectivelyrendering said different speed ratios effective and connections betweensaid control member and the throttle of said engine for automaticallyshutting off and releasing the pressure being delivered to said fluidpressure actuated means whenever said throttle is moved to closedposition, thereby to establish a free wheeling condition.

10. In a fluid pressure actuated change speed I transmission, a drivingshaft and a driven shaft,

means for establishing a plurality of different driving ratios betweensaid driving and driven shafts including clutch means, a source of fluidpressure, fluid pressure actuated means for operating said clutch means,a control member interposed between said source of fluid pressure andsaid fluid pressure actuated means'for selectively .rendering saiddifferent speed ratios effective.

and means including said control member for varying the pressure of thefluid delivered to said fluid pressure actuated means from said source.

11. The combination with an automobile having a throttle controlledengine, of a fluid pressure actuated change speed transmission com--.prising a driving shaft and a driven shaft, means for establishing aplurality of diii'erent driving ratios between said driving and drivenshafts including clutch means, a source of fluid pressure, fluidpressure actuated means for operating said clutch means, a controlmember interposed between said source of fluid pressure and said fluidpressure actuated means for selectively rendering said diflferent speedratios effective and connections between said control member and thethrottle of said engine for automatically shutting off and releasing thepressure being delivered to said fluid pressure actuated means wheneversaid throttle is moved to closed position, thereby to establish a freewheeling condition.

12. In a transmission, a driving shaft, a driven shaft, clutch means forconnecting said shafts in operative driving engagement, fluid pressureactuated clutch engaging means including means of resilient effect toproduce gradual increase in clutch pressure in accordance with theamount of fluid transmitted thereto, and means for regulating the rateof flow thereby to regulate the rate of clutch engagement.

13. An automatic fluid pressure controlled change speed transmission foran automobile having a throttle controlled engine and a manuallyoperated device for actuating said throttle, characterized by aplurality of fluid pressure operated clutches for selectively makingdiflerent gear ratios effective, a pump for supply g fluid underpressure to said clutches, a pressure control valve for governing thepressure of the fluid delivered by said pump to said clutches, andconnections between said pressure control valve and throttle actuatingmember for regulating the extent of opening of said pressure controlvalve and thereby the pressure of the fluid delivered to said clutchesin accordance with the extent of throttle opening.

14. An automatic fluid pressure controlled change speed transmission foran automobile having a throttle controlled engine and a manuallyoperated device for actuating said throttle, characterized by aplurality of fluid pressure operated clutches for selectively makingdifferent gear ratios efiective, a pump for supplying fluid underpressure to said clutches, a pressure control valve for governing thepressure of the fluid delivered by said pump to said clutches, andconnections between said pressure control valve and throttle actuatingmember for regulating pressure oi the fluid delivered to said clutchesin accordance with the extent of throttle opening.

WILLIAM TQLIVERMORE.

